Hard to say, as there isn't a whole lot of precedent for these types of deals, but I'd disagree. The closest would be Turris to Ottawa, which isn't a perfect match, but it's pretty close (both were 3rd overall picks who asked for trades, with rather unimpressive rookie seasons - Turris was a year older, though). Ottawa gave up Rundblad (a relatively well regarded but not quite blue chip prospect at the time) and a 2nd round pick. Drouin may have slightly more value, as his ceiling is expected to be a little higher than Turris' was at the time (not drastically, though - 70-75 point player compared to a 60-65 point one). So, his value on his own is probably pretty similar.
I think sometimes we forget that prospects, no matter how highly touted, generally don't have the kind of trade value we ascribe to them (elite, freshly drafted players like McDavid excepted, of course). Could Drouin one day be more valuable than JvR? Absolutely. In fact, for any team interested in trading for him, that's the hope. However, in terms of value on the trade market, he's not there yet.
